This invention relates to a tire-slip preventing device and more particularly to a tire-slip preventing device for preventing the tires of a car from slipping on an icy, snowy or muddy road.
For many years, tire-slip preventing devices made of chains have been available on the market. These devices employ a ladder-like arrangement of chains together with a fastening means for connecting one end of each "side" of the ladder to the other end of the same side, after the device has been wrapped around the periphery of a tire.
There has recently been proposed a tire-slip preventing device which generally comprises two opposed parallel cords and a plurality of cross belts all made from synthetic resin or some other tough but easily deformable material. The cross belts are connected laterally to the cords at the two ends by a suitable fastening and rivet means so that when the device is laid out in a plane it has the form of a ladder, just as the well-known "chains". Each cord is provided with connecting means at the two ends, to be coupled and linked with each other after the device has been wrapped about a tire.
The recently proposed tire-slip preventing device has numerous advantages over the old tire chain made of metal. It is light, easy to carry, and rust-proof. It has the advantage of causing much less damage to the road surface over which the vehicle travels. Furthermore, when the vehicle travels, noise from the device is remarkably less than for the chain device. Nevertheless, it has an important drawback in that the side walls of the tire are inevitably damaged by the end portions of the cross belts when the device is mounted on a vehicle tire and the vehicle is driven to rotate the tire. The cross belts are connected with the cords and are disposed at substantially equal distances around the periphery of the tire, with the two end portions of the respective cross belts being deformably folded and closely held against the side walls of the tire. Thus, when the tire carrying the device is rotated, sliding forces are exerted by the middle portion of the cross belts on the tread portion of the tire every time a cross belt engages the ground. This causes the two end portions of the cross belts to conduct swing and follow movements against the side walls of the tire against which they are fairly tightly held, thereby causing excessive frictional damage to the side walls of the tire. In an extreme case bursting the tire may occur.